Researchers at the International Group for Historic Aircraft Recovery (TIGHAR) revealed that a piece from Amelia Earhart’s missing airplane has been identified in Nikumaroro, an atoll in the southwestern Pacific republic of Kiribati. This is the first time that an artifact from the wreckage has been directly linked to Earhart’s last journey, in which she attempted to circumnavigate the Earth at the equator, and reveals new evidence on the 77-year-old aviation mystery.

The 19-inch-wide by 23-inch-long piece, discovered by researchers in 1991, is strongly believed to be a metal fragment installed on the window of Earhart’s Lockheed Electra aircraft during her eight-day stay in Miami, which was the fourth stop on her trip. A photograph on TIGHAR’s site from The Miam...